/**
 * Object.getOwnPropertySymbols 遍历自身Symbol类型的属性
 */
class Father {
	constructor(name, age) {
		this.name = name
		this.age = age
	}
	number = 12
	getAge() {
		return this.age
	}
}
Father.prototype.expand = () => {}
class Child extends Father {
	constructor(name, age) {
		super(name, age)
		this[Symbol('sex')] = '男'
	}
}
const obj = new Child('zs', 18)
Object.defineProperty(obj, 'name', {
	enumerable: false,
})
console.log(Object.getOwnPropertySymbols(obj))
// [ Symbol(sex)]
